BEIJING — Underage interns working at a plant operated by electronics manufacturing giant Foxconn Technology Group returned to their vocational schools in the eastern Chinese city of Yantai on Wednesday, the official New China News Agency reported.

Foxconn on Tuesday admitted to employing interns as young as 14 at a factory in the city. China’s minimum working age is 16. It’s unclear how many workers were underage.

“Our investigation has shown that the interns in question, who ranged in age from 14 to 16, had worked in that campus for approximately three weeks,” Foxconn said in a prepared statement. “We have found no evidence of similar violations in any of our other campuses in China, but we will not hesitate to take immediate action in any campus if any violations are discovered.”

The admission comes one month after Foxconn denied reports in Chinese media that it forced vocational students to work in factories making iPhones.

State media reported that the teenagers were among thousands of students tabbed by vocational schools in the area to help solve severe labor shortages at Foxconn plants. Foxconn reportedly sought help from the local government in finding workers.

“Foxconn has long had a short-term internship program that we carry out in cooperation with a number of vocational schools and other educational institutions in China,” the company said. “The internship programs range from three to six months in duration, with the average being 3.5 months. Interns represent approximately 2.7 percent of our workforce of 1.2 million employees in China.”

The company is most famous for manufacturing some of Apple’s (AAPL) most popular products. It has come under fire in recent years for a rash of employee suicides and campus protests and riots.

The company has agreed to third-party audits, however, and pays some of the highest wages for factory work in the country.